TY - JOUR
A1 - Birnick, Johann
A1 - Bläsius, Thomas
A1 - Friedrich, Tobias
A1 - Naumann, Felix
A1 - Papenbrock, Thorsten
A1 - Schirneck, Friedrich Martin
T1 - Hitting set enumeration with partial information for unique column combination discovery
JF - Proceedings of the VLDB Endowment
N2 - Unique column combinations (UCCs) are a fundamental concept in relational databases. They identify entities in the data and support various data management activities. Still, UCCs are usually not explicitly defined and need to be discovered. State-of-the-art data profiling algorithms are able to efficiently discover UCCs in moderately sized datasets, but they tend to fail on large and, in particular, on wide datasets due to run time and memory limitations.
In this paper, we introduce HPIValid, a novel UCC discovery algorithm that implements a faster and more resource-saving search strategy. HPIValid models the metadata discovery as a hitting set enumeration problem in hypergraphs. In this way, it combines efficient discovery techniques from data profiling research with the most recent theoretical insights into enumeration algorithms. Our evaluation shows that HPIValid is not only orders of magnitude faster than related work, it also has a much smaller memory footprint.
Y1 - 2020
U6 - https://doi.org/10.14778/3407790.3407824
SN - 2150-8097
VL - 13
IS - 11
SP - 2270
EP - 2283
PB - Association for Computing Machinery
CY - [New York, NY]
ER -
TY - JOUR
A1 - Blaesius, Thomas
A1 - Friedrich, Tobias
A1 - Schirneck, Friedrich Martin
T1 - The complexity of dependency detection and discovery in relational databases
JF - Theoretical computer science
N2 - Multi-column dependencies in relational databases come associated with two different computational tasks. The detection problem is to decide whether a dependency of a certain type and size holds in a given database, the discovery problem asks to enumerate all valid dependencies of that type. We settle the complexity of both of these problems for unique column combinations (UCCs), functional dependencies (FDs), and inclusion dependencies (INDs). We show that the detection of UCCs and FDs is W[2]-complete when parameterized by the solution size. The discovery of inclusion-wise minimal UCCs is proven to be equivalent under parsimonious reductions to the transversal hypergraph problem of enumerating the minimal hitting sets of a hypergraph. The discovery of FDs is equivalent to the simultaneous enumeration of the hitting sets of multiple input hypergraphs. We further identify the detection of INDs as one of the first natural W[3]-complete problems. The discovery of maximal INDs is shown to be equivalent to enumerating the maximal satisfying assignments of antimonotone, 3-normalized Boolean formulas.
KW - data profiling
KW - enumeration complexity
KW - functional dependency
KW - inclusion
KW - dependency
KW - parameterized complexity
KW - parsimonious reduction
KW - transversal hypergraph
KW - Unique column combination
KW - W[3]-completeness
Y1 - 2021
U6 - https://doi.org/10.1016/j.tcs.2021.11.020
SN - 0304-3975
SN - 1879-2294
VL - 900
SP - 79
EP - 96
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Bläsius, Thomas
A1 - Friedrich, Tobias
A1 - Lischeid, Julius
A1 - Meeks, Kitty
A1 - Schirneck, Friedrich Martin
T1 - Efficiently enumerating hitting sets of hypergraphs arising in data profiling
JF - Journal of computer and system sciences : JCSS
N2 - The transversal hypergraph problem asks to enumerate the minimal hitting sets of a hypergraph. If the solutions have bounded size, Eiter and Gottlob [SICOMP'95] gave an algorithm running in output-polynomial time, but whose space requirement also scales with the output. We improve this to polynomial delay and space. Central to our approach is the extension problem, deciding for a set X of vertices whether it is contained in any minimal hitting set. We show that this is one of the first natural problems to be W[3]-complete. We give an algorithm for the extension problem running in time O(m(vertical bar X vertical bar+1) n) and prove a SETH-lower bound showing that this is close to optimal. We apply our enumeration method to the discovery problem of minimal unique column combinations from data profiling. Our empirical evaluation suggests that the algorithm outperforms its worst-case guarantees on hypergraphs stemming from real-world databases.
KW - Data profiling
KW - Enumeration algorithm
KW - Minimal hitting set
KW - Transversal hypergraph
KW - Unique column combination
KW - W[3]-Completeness
Y1 - 2022
U6 - https://doi.org/10.1016/j.jcss.2021.10.002
SN - 0022-0000
SN - 1090-2724
VL - 124
SP - 192
EP - 213
PB - Elsevier
CY - San Diego
ER -
TY - GEN
A1 - Blaesius, Thomas
A1 - Eube, Jan
A1 - Feldtkeller, Thomas
A1 - Friedrich, Tobias
A1 - Krejca, Martin Stefan
A1 - Lagodzinski, Gregor J. A.
A1 - Rothenberger, Ralf
A1 - Severin, Julius
A1 - Sommer, Fabian
A1 - Trautmann, Justin
T1 - Memory-restricted Routing With Tiled Map Data
T2 - 2018 IEEE International Conference on Systems, Man, and Cybernetics (SMC)
N2 - Modern routing algorithms reduce query time by depending heavily on preprocessed data. The recently developed Navigation Data Standard (NDS) enforces a separation between algorithms and map data, rendering preprocessing inapplicable. Furthermore, map data is partitioned into tiles with respect to their geographic coordinates. With the limited memory found in portable devices, the number of tiles loaded becomes the major factor for run time. We study routing under these restrictions and present new algorithms as well as empirical evaluations. Our results show that, on average, the most efficient algorithm presented uses more than 20 times fewer tile loads than a normal A*.
Y1 - 2018
SN - 978-1-5386-6650-0
U6 - https://doi.org/10.1109/SMC.2018.00567
SN - 1062-922X
SP - 3347
EP - 3354
PB - IEEE
CY - New York
ER -
TY - JOUR
A1 - Günther, Oliver
A1 - Mangelsdorf, Birgit
A1 - Mitzner, Rolf
A1 - Loschelder, Wolfgang
A1 - Peter, Andreas
A1 - Eckert, Barbara
A1 - Mikelskis, Helmut
A1 - Klein, Alfred
A1 - Kirsch, Bärbel
A1 - Edelstein, Wolfgang
A1 - Thomas, Grünewald
A1 - Thomas, Pösl
A1 - Wagner, Dieter
A1 - Winskowski, Friedrich
A1 - Schad, Martina
A1 - Frey, Anne
A1 - Bickenbach, Wulf
A1 - Madani, Roya
A1 - Olaka, Lydia
T1 - Portal alumni
T2 - Das Ehemaligen-Magazin der Universität Potsdam
N2 - Das zurückliegende Jahr stand an der Universität Potsdam auch im Zeichen des zwanzigjährigen Jubiläums der Hochschule. Am 15. Juli 1991, wurde sie gegründet und während einer Festwoche feierten Professorinnen und Professoren, Mitarbeiterinnen, Mitarbeiter und Studierende dieses Jubiläum gebührend. Seit der Gründung der größten brandenburgischen Hochschule sind wissenschaftliches Renommee, Ansehen und Attraktivität stetig gewachsen. Gerade in den letzten Jahren hat sie ihr Profil geschärft. Vor allem die Kognitions-, die Geo- und Biowissenschaften sind hier zu nennen. Aber auch die Lehrerbildung besitzt einen hohen Stellenwert. International anerkannte Forschungsbereiche, Wissenschaftspreise, eine erfolgreiche Drittmittelbilanz und nicht zuletzt die bauliche Entwicklung an allen drei Standorten sind sichtbare Indikatoren für die erfolgreiche Entwicklung, die die Universität Potsdam in den letzten zwei Jahrzehnten durchlaufen hat. Die drei ehemaligen Präsidenten sowie verschiedene andere Protagonisten werfen in dieser Ausgabe der Portal Alumni einen Blick auf unterschiedliche Aspekte der zurückliegenden Entwicklung der Universität. Vom Erfolg der Universität zeugt auch die wachsende Zahl der Absolventinnen und Absolventen, die die Universität verlassen. Portal Alumni stellt in der vorliegenden Ausgabe deshalb Absolventen und deren universitäre und berufliche Lebenswege genauer vor und lässt damit zugleich kaleidoskopartig 20 Jahre Studium an der Universität Potsdam Revue passieren.
T3 - Portal alumni : das Ehemaligen-Magazin der Universität Potsdam - 9/2012
Y1 - 2012
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-444943
SN - 1613-2343
IS - 9
ER -
TY - JOUR
A1 - Vorburger, Thomas
A1 - Nedielkov, Ruslan
A1 - Brosig, Alexander
A1 - Bok, Eva
A1 - Schunke, Emina
A1 - Steffen, Wojtek
A1 - Mayer, Sonja
A1 - Goetz, Friedrich
A1 - Möller, Heiko Michael
A1 - Steuber, Julia
T1 - Role of the Na+-translocating NADH:quinone oxidoreductase in voltage generation and Na+ extrusion in Vibrio cholerae
JF - Biochimica et biophysica acta : Bioenergetics
N2 - For Vibrio cholerae, the coordinated import and export of Na+ is crucial for adaptation to habitats with different osmolarities. We investigated the Na+-extruding branch of the sodium cycle in this human pathogen by in vivo Na-23-NMR spectroscopy. The Na+ extrusion activity of cells was monitored after adding glucose which stimulated respiration via the Na+-translocating NADH:quinone oxidoreductase (Na+-NQR). In a V. cholerae deletion mutant devoid of the Na+-NQR encoding genes (nqrA-F), rates of respiratory Na+ extrusion were decreased by a factor of four, but the cytoplasmic Na+ concentration was essentially unchanged. Furthermore, the mutant was impaired in formation of transmembrane voltage (Delta psi, inside negative) and did not grow under hypoosmotic conditions at pH 8.2 or above. This growth defect could be complemented by transformation with the plasmid encoded nqr operon. In an alkaline environment, Na+/H+ antiporters acidify the cytoplasm at the expense of the transmembrane voltage. It is proposed that, at alkaline pH and limiting Na+ concentrations, the Na+-NQR is crucial for generation of a transmembrane voltage to drive the import of H+ by electrogenic Na+/H+ antiporters. Our study provides the basis to understand the role of the Na+-NQR in pathogenicity of V. cholerae and other pathogens relying on this primary Na+ pump for respiration. (C) 2015 Elsevier B.V. All rights reserved.
KW - Nuclear magnetic resonance (NMR)
KW - Sodium transport
KW - Vibrio cholerae
KW - Respiration
KW - Na+ homeostasis
KW - Hypoosmotic stress
Y1 - 2016
U6 - https://doi.org/10.1016/j.bbabio.2015.12.010
SN - 0005-2728
SN - 0006-3002
VL - 1857
SP - 473
EP - 482
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Friedrich, Tobias
A1 - Krejca, Martin Stefan
A1 - Rothenberger, Ralf
A1 - Arndt, Tobias
A1 - Hafner, Danijar
A1 - Kellermeier, Thomas
A1 - Krogmann, Simon
A1 - Razmjou, Armin
T1 - Routing for on-street parking search using probabilistic data
JF - AI communications : AICOM ; the European journal on artificial intelligence
N2 - A significant percentage of urban traffic is caused by the search for parking spots. One possible approach to improve this situation is to guide drivers along routes which are likely to have free parking spots. The task of finding such a route can be modeled as a probabilistic graph problem which is NP-complete. Thus, we propose heuristic approaches for solving this problem and evaluate them experimentally. For this, we use probabilities of finding a parking spot, which are based on publicly available empirical data from TomTom International B.V. Additionally, we propose a heuristic that relies exclusively on conventional road attributes. Our experiments show that this algorithm comes close to the baseline by a factor of 1.3 in our cost measure. Last, we complement our experiments with results from a field study, comparing the success rates of our algorithms against real human drivers.
KW - Parking search
KW - probabilistic routing
KW - constrained optimization
KW - field study
Y1 - 2019
U6 - https://doi.org/10.3233/AIC-180574
SN - 0921-7126
SN - 1875-8452
VL - 32
IS - 2
SP - 113
EP - 124
PB - IOS Press
CY - Amsterdam
ER -
TY - JOUR
A1 - Prasse, Rüdiger
A1 - Ristow, Michael
A1 - Klemm, Gunther
A1 - Machatzi, Bernd
A1 - Raus, Thomas
A1 - Scholz, Hildemar
A1 - Stohr, Gerrit
A1 - Sukopp, Herbert
A1 - Zimmermann, Friedrich
T1 - Liste der wildwachsenden Gefäßpflanzen des Landes Berlin : mit Roter Liste
Y1 - 2001
SN - 3-88961-137-0
PB - Kulturbuch-Verl.
CY - Berlin
ER -
TY - JOUR
A1 - Castellanos, Reynel Urrea
A1 - Friedrich, Thomas
A1 - Petrovic, Nevena
A1 - Altmann, Simone
A1 - Brzezinka, Krzysztof
A1 - Gorka, Michal
A1 - Graf, Alexander
A1 - Bäurle, Isabel
T1 - FORGETTER2 protein phosphatase and phospholipase D modulate heat stress memory in Arabidopsis
JF - The plant journal
N2 - Plants can mitigate environmental stress conditions through acclimation. In the case of fluctuating stress conditions such as high temperatures, maintaining a stress memory enables a more efficient response upon recurring stress. In a genetic screen forArabidopsis thalianamutants impaired in the memory of heat stress (HS) we have isolated theFORGETTER2(FGT2) gene, which encodes a type 2C protein phosphatase (PP2C) of the D-clade.Fgt2mutants acquire thermotolerance normally; however, they are defective in the memory of HS. FGT2 interacts with phospholipase D alpha 2 (PLD alpha 2), which is involved in the metabolism of membrane phospholipids and is also required for HS memory. In summary, we have uncovered a previously unknown component of HS memory and identified the FGT2 protein phosphatase and PLD alpha 2 as crucial players, suggesting that phosphatidic acid-dependent signaling or membrane composition dynamics underlie HS memory.
KW - priming
KW - protein phosphatase
KW - stress memory
KW - heat stress
KW - Arabidopsis
KW - thaliana
Y1 - 2020
U6 - https://doi.org/10.1111/tpj.14927
SN - 0960-7412
SN - 1365-313X
VL - 104
IS - 1
SP - 7
EP - 17
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Kabelitz, Tina
A1 - Brzezinka, Krzysztof
A1 - Friedrich, Thomas
A1 - Gorka, Michal
A1 - Graf, Alexander
A1 - Kappel, Christian
A1 - Bäurle, Isabel
T1 - A JUMONJI Protein with E3 Ligase and Histone H3 Binding Activities Affects Transposon Silencing in Arabidopsis
JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants
N2 - Transposable elements (TEs) make up a large proportion of eukaryotic genomes. As their mobilization creates genetic variation that threatens genome integrity, TEs are epigenetically silenced through several pathways, and this may spread to neighboring sequences. JUMONJI (JMJ) proteins can function as antisilencing factors and prevent silencing of genes next to TEs. Whether TE silencing is counterbalanced by the activity of antisilencing factors is still unclear. Here, we characterize JMJ24 as a regulator of TE silencing. We show that loss of JMJ24 results in increased silencing of the DNA transposon AtMu1c, while overexpression of JMJ24 reduces silencing. JMJ24 has a JumonjiC (JmjC) domain and two RING domains. JMJ24 autoubiquitinates in vitro, demonstrating E3 ligase activity of the RING domain(s). JMJ24-JmjC binds the N-terminal tail of histone H3, and full-length JMJ24 binds histone H3 in vivo. JMJ24 activity is anticorrelated with histone H3 Lys 9 dimethylation (H3K9me2) levels at AtMu1c. Double mutant analyses with epigenetic silencing mutants suggest that JMJ24 antagonizes histone H3K9me2 and requires H3K9 methyltransferases for its activity on AtMu1c. Genome-wide transcriptome analysis indicates that JMJ24 affects silencing at additional TEs. Our results suggest that the JmjC domain of JMJ24 has lost demethylase activity but has been retained as a binding domain for histone H3. This is in line with phylogenetic analyses indicating that JMJ24 (with the mutated JmjC domain) is widely conserved in angiosperms. Taken together, this study assigns a role in TE silencing to a conserved JmjC-domain protein with E3 ligase activity, but no demethylase activity.
Y1 - 2016
U6 - https://doi.org/10.1104/pp.15.01688
SN - 0032-0889
SN - 1532-2548
VL - 171
SP - 344
EP - 358
PB - American Society of Plant Physiologists
CY - Rockville
ER -
TY - JOUR
A1 - Debatin, Franziska
A1 - Thomas, Arne
A1 - Kelling, Alexandra
A1 - Hedin, Niklas
A1 - Bacsik, Zoltan
A1 - Senkovska, Irena
A1 - Kaskel, Stefan
A1 - Junginger, Matthias
A1 - Müller, Holger
A1 - Schilde, Uwe
A1 - Jäger, Christian
A1 - Friedrich, Alwin
A1 - Holdt, Hans-Jürgen
T1 - In situ synthesis of an imidazolate-4-amide-5-imidate ligand and formation of a microporous zinc-organic framework with H2-and CO2-storage ability
N2 - Narrow channels with polar walls are the structural and functional features responsible for the high capacity of a zinc-organic framework based on an imidazolate-amide-imidate ligand for the uptake of H2 and CO2 (see structure: orange Zn, blue N, red O, dark gray C, light gray H). The rigid and stable chelating ligand was synthesized in situ by partial hydrolysis of a dicyanoimidazole compound.
Y1 - 2010
UR - http://www3.interscience.wiley.com/cgi-bin/jhome/26737/
U6 - https://doi.org/10.1002/anie.200906188
SN - 1433-7851
ER -
TY - JOUR
A1 - Meier, Johann Georg
A1 - Stumpe, Joachim
A1 - Fischer, Birgit
A1 - Thieme, Cathrin
A1 - Fischer, Thomas M.
A1 - Kremer, Friedrich
A1 - Öge, Tanja
A1 - Zentel, Rudolf
T1 - Optical suppression of Ferroelectricity in polysiloxane copolymers with chiral an potochromic side groups
Y1 - 1998
ER -
TY - GEN
A1 - Chaykovska, Lyubov
A1 - Heunisch, Fabian
A1 - von Einem, Gina
A1 - Alter, Markus L.
A1 - Hocher, Carl-Friedrich
A1 - Tsuprykov, Oleg
A1 - Dschietzig, Thomas
A1 - Kretschmer, Axel
A1 - Hocher, Berthold
T1 - Urinary vitamin D binding protein and KIM-1 are potent new biomarkers of major adverse renal events in patients undergoing coronary angiography
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Background
Vitamin-D-binding protein (VDBP) is a low molecular weight protein that is filtered through the glomerulus as a 25-(OH) vitamin D 3/VDBP complex. In the normal kidney VDBP is reabsorbed and catabolized by proximal tubule epithelial cells reducing the urinary excretion to trace amounts. Acute tubular injury is expected to result in urinary VDBP loss. The purpose of our study was to explore the potential role of urinary VDBP as a biomarker of an acute renal damage.
Method
We included 314 patients with diabetes mellitus or mild renal impairment undergoing coronary angiography and collected blood and urine before and 24 hours after the CM application. Patients were followed for 90 days for the composite endpoint major adverse renal events (MARE: need for dialysis, doubling of serum creatinine after 90 days, unplanned emergency rehospitalization or death).
Results
Increased urine VDBP concentration 24 hours after contrast media exposure was predictive for dialysis need (no dialysis: 113.06 +/- 299.61ng/ml, n = 303; need for dialysis: 613.07 +/- 700.45 ng/ml, n = 11, Mean +/- SD, p < 0.001), death (no death during follow-up: 121.41 +/- 324.45 ng/ml, n = 306; death during follow-up: 522.01 +/- 521.86 ng/ml, n = 8; Mean +/- SD, p < 0.003) and MARE (no MARE: 112.08 +/- 302.00ng/ml, n = 298; MARE: 506.16 +/- 624.61 ng/ml, n = 16, Mean +/- SD, p < 0.001) during the follow-up of 90 days after contrast media exposure. Correction of urine VDBP concentrations for creatinine excretion confirmed its predictive value and was consistent with increased levels of urinary Kidney Injury Molecule1 (KIM-1) and baseline plasma creatinine in patients with above mentioned complications. The impact of urinary VDBP and KIM-1 on MARE was independent of known CIN risk factors such as anemia, preexisting renal failure, preexisting heart failure, and diabetes.
Conclusions
Urinary VDBP is a promising novel biomarker of major contrast induced nephropathy-associated events 90 days after contrast media exposure.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 558
KW - acute kidney injury
KW - cardiac surgery
KW - molecule-1 KIM-1
KW - early diagnosis
KW - failure
KW - intervention
KW - disease
KW - NGAL
Y1 - 2019
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-411928
SN - 1866-8372
IS - 558
ER -
TY - JOUR
A1 - Chaykovska, Lyubov
A1 - Heunisch, Fabian
A1 - von Einem, Gina
A1 - Alter, Markus L.
A1 - Hocher, Carl-Friedrich
A1 - Tsuprykov, Oleg
A1 - Dschietzig, Thomas
A1 - Kretschmer, Axel
A1 - Hocher, Berthold
T1 - Urinary Vitamin D Binding Protein and KIM-1 Are Potent New Biomarkers of Major Adverse Renal Events in Patients Undergoing Coronary Angiography
JF - PLoS one
N2 - Background Vitamin-D-binding protein (VDBP) is a low molecular weight protein that is filtered through the glomerulus as a 25-(OH) vitamin D 3/VDBP complex. In the normal kidney VDBP is reabsorbed and catabolized by proximal tubule epithelial cells reducing the urinary excretion to trace amounts. Acute tubular injury is expected to result in urinary VDBP loss. The purpose of our study was to explore the potential role of urinary VDBP as a biomarker of an acute renal damage. Method We included 314 patients with diabetes mellitus or mild renal impairment undergoing coronary angiography and collected blood and urine before and 24 hours after the CM application. Patients were followed for 90 days for the composite endpoint major adverse renal events (MARE: need for dialysis, doubling of serum creatinine after 90 days, unplanned emergency rehospitalization or death). Results Increased urine VDBP concentration 24 hours after contrast media exposure was predictive for dialysis need (no dialysis: 113.06 +/- 299.61ng/ml, n = 303; need for dialysis: 613.07 +/- 700.45 ng/ml, n = 11, Mean +/- SD, p < 0.001), death (no death during follow-up: 121.41 +/- 324.45 ng/ml, n = 306; death during follow-up: 522.01 +/- 521.86 ng/ml, n = 8; Mean +/- SD, p < 0.003) and MARE (no MARE: 112.08 +/- 302.00ng/ml, n = 298; MARE: 506.16 +/- 624.61 ng/ml, n = 16, Mean +/- SD, p < 0.001) during the follow-up of 90 days after contrast media exposure. Correction of urine VDBP concentrations for creatinine excretion confirmed its predictive value and was consistent with increased levels of urinary Kidney Injury Molecule1 (KIM-1) and baseline plasma creatinine in patients with above mentioned complications. The impact of urinary VDBP and KIM-1 on MARE was independent of known CIN risk factors such as anemia, preexisting renal failure, preexisting heart failure, and diabetes. Conclusions Urinary VDBP is a promising novel biomarker of major contrast induced nephropathy-associated events 90 days after contrast media exposure.
Y1 - 2016
U6 - https://doi.org/10.1371/journal.pone.0145723
SN - 1932-6203
VL - 11
PB - PLoS
CY - San Fransisco
ER -
TY - JOUR
A1 - Bläsius, Thomas
A1 - Freiberger, Cedric
A1 - Friedrich, Tobias
A1 - Katzmann, Maximilian
A1 - Montenegro-Retana, Felix
A1 - Thieffry, Marianne
T1 - Efficient Shortest Paths in Scale-Free Networks with Underlying Hyperbolic Geometry
JF - ACM Transactions on Algorithms
N2 - A standard approach to accelerating shortest path algorithms on networks is the bidirectional search, which explores the graph from the start and the destination, simultaneously. In practice this strategy performs particularly well on scale-free real-world networks. Such networks typically have a heterogeneous degree distribution (e.g., a power-law distribution) and high clustering (i.e., vertices with a common neighbor are likely to be connected themselves). These two properties can be obtained by assuming an underlying hyperbolic geometry.
To explain the observed behavior of the bidirectional search, we analyze its running time on hyperbolic random graphs and prove that it is (O) over tilde (n(2-1/alpha) + n(1/(2 alpha)) + delta(max)) with high probability, where alpha is an element of (1/2, 1) controls the power-law exponent of the degree distribution, and dmax is the maximum degree. This bound is sublinear, improving the obvious worst-case linear bound. Although our analysis depends on the underlying geometry, the algorithm itself is oblivious to it.
KW - Random graphs
KW - hyperbolic geometry
KW - scale-free networks
KW - bidirectional shortest path
Y1 - 2022
U6 - https://doi.org/10.1145/3516483
SN - 1549-6325
SN - 1549-6333
VL - 18
IS - 2
SP - 1
EP - 32
PB - Association for Computing Machinery
CY - New York
ER -
TY - JOUR
A1 - Debatin, Franziska
A1 - Behrens, Karsten
A1 - Weber, Jens
A1 - Baburin, Igor A.
A1 - Thomas, Arne
A1 - Schmidt, Johannes
A1 - Senkovska, Irena
A1 - Kaskel, Stefan
A1 - Kelling, Alexandra
A1 - Hedin, Niklas
A1 - Bacsik, Zoltan
A1 - Leoni, Stefano
A1 - Seifert, Gotthard
A1 - Jäger, Christian
A1 - Günter, Christina
A1 - Schilde, Uwe
A1 - Friedrich, Alwin
A1 - Holdt, Hans-Jürgen
T1 - An isoreticular family of microporous metal-organic frameworks based on zinc and 2-substituted imidazolate-4-amide-5-imidate Syntheses, structures and properties
JF - Chemistry - a European journal
N2 - We report on a new series of isoreticular frameworks based on zinc and 2-substituted imidazolate-4-amide-5-imidate (IFP-14, IFP=imidazolate framework Potsdam) that form one-dimensional, microporous hexagonal channels. Varying R in the 2-substitued linker (R=Me (IFP-1), Cl (IFP-2), Br (IFP-3), Et (IFP-4)) allowed the channel diameter (4.01.7 angstrom), the polarisability and functionality of the channel walls to be tuned. Frameworks IFP-2, IFP-3 and IFP-4 are isostructural to previously reported IFP-1. The structures of IFP-2 and IFP-3 were solved by X-ray crystallographic analyses. The structure of IFP-4 was determined by a combination of PXRD and structure modelling and was confirmed by IR spectroscopy and 1H MAS and 13C CP-MAS NMR spectroscopy. All IFPs showed high thermal stability (345400?degrees C); IFP-1 and IFP-4 were stable in boiling water for 7 d. A detailed porosity analysis was performed on the basis of adsorption measurements by using various gases. The potential of the materials to undergo specific interactions with CO2 was investigated by measuring the isosteric heats of adsorption. The capacity to adsorb CH4 (at 298 K), CO2 (at 298 K) and H2 (at 77 K) at high pressure were also investigated. In situ IR spectroscopy showed that CO2 is physisorbed on IFP-14 under dry conditions and that both CO2 and H2O are physisorbed on IFP-1 under moist conditions.
KW - adsorption
KW - metal- organic frameworks
KW - microporous materials
KW - N
KW - O ligands
KW - zinc
Y1 - 2012
U6 - https://doi.org/10.1002/chem.201200889
SN - 0947-6539
VL - 18
IS - 37
SP - 11630
EP - 11640
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Friedrich, Thomas
A1 - Oberkofler, Vicky
A1 - Trindade, Inês
A1 - Altmann, Simone
A1 - Brzezinka, Krzysztof
A1 - Lämke, Jörn S.
A1 - Gorka, Michal
A1 - Kappel, Christian
A1 - Sokolowska, Ewelina
A1 - Skirycz, Aleksandra
A1 - Graf, Alexander
A1 - Bäurle, Isabel
T1 - Heteromeric HSFA2/HSFA3 complexes drive transcriptional memory after heat stress in Arabidopsis
JF - Nature Communications
N2 - Adaptive plasticity in stress responses is a key element of plant survival strategies. For instance, moderate heat stress (HS) primes a plant to acquire thermotolerance, which allows subsequent survival of more severe HS conditions. Acquired thermotolerance is actively maintained over several days (HS memory) and involves the sustained induction of memory-related genes. Here we show that FORGETTER3/ HEAT SHOCK TRANSCRIPTION FACTOR A3 (FGT3/HSFA3) is specifically required for physiological HS memory and maintaining high memory-gene expression during the days following a HS exposure. HSFA3 mediates HS memory by direct transcriptional activation of memory-related genes after return to normal growth temperatures. HSFA3 binds HSFA2, and in vivo both proteins form heteromeric complexes with additional HSFs. Our results indicate that only complexes containing both HSFA2 and HSFA3 efficiently promote transcriptional memory by positively influencing histone H3 lysine 4 (H3K4) hyper-methylation. In summary, our work defines the major HSF complex controlling transcriptional memory and elucidates the in vivo dynamics of HSF complexes during somatic stress memory. Moderate heat stress primes plants to acquire tolerance to subsequent, more severe heat stress. Here the authors show that the HSFA3 transcription factor forms a heteromeric complex with HSFA2 to sustain activated transcription of genes required for acquired thermotolerance by promoting H3K4 hyper-methylation.
Y1 - 2021
U6 - https://doi.org/10.1038/s41467-021-23786-6
SN - 2041-1723
VL - 12
IS - 1
PB - Nature Publishing Group UK
CY - [London]
ER -
TY - BOOK
A1 - Beck, Lorenz Friedrich
A1 - Schoeps, Julius H.
A1 - Gerber, Thomas
A1 - Zabel, Marco
T1 - Der Soldatenkönig : Friedrich Wilhelm I. in seiner Zeit
T3 - Brandenburgische Historische Schriften
Y1 - 2003
SN - 3-935035-43-8
VL - 12
PB - Verl. für Berlin-Brandenburg
CY - Potsdam
ER -
TY - JOUR
A1 - Voss, Henning
A1 - Meyer, Jeannette
A1 - Schwonbeck, Susanne
A1 - Fritsche, Immo
A1 - Hartmann, Bernhard
A1 - Wegwarth, Odette
A1 - Friedrich, Anke
A1 - Buchheister-Knappe, Stefanie
A1 - Marwan, Norbert
A1 - Bandau, Anja
A1 - Bullinger, Hans-Jörg
A1 - Weith, Thomas
T1 - Portal alumni
T2 - Das Ehemaligen-Magazin der Universität Potsdam
N2 - Liebe Leserin, lieber Leser, erforschen, was die Welt im Innersten zusammenhält- das ist für viele Studierende ein Traum. Doch welche Opfer muss man bringen, um ihn zu verwirklichen? Welche Bemfsperspektive hat der Bemf Forscher heute noch? Auch viele Absolventen der Universität Potsdam müssen sich diese Fragen beantworten. Zu welchen Antworten einige dabei gekommen sind und welche Probleme sie zu bewältigen haben, vom Spaß am Forschen und von Zukunftsängsten berichten sie in der Rubrik "Forscherkarrieren". Gelder für die Forschung fließen in Deutschland zu spärlich, verglichen mit anderen führenden Industrienationen. So sind die Bedingungen für Forscher hierzulande nicht die besten. Manchen jungen Wissenschaftler zieht es- mitunter notgedrungen- ins Ausland. Wie Deutschland dadurch seine ZukunftsHihigkeit riskiert, thematisiert der Präsident der Fraunhofer-Gesellschaft, Prof. Dr. Hans-Jörg Bullinger, in der Rubrik "wissenstransfer". Auch die Universität ist kein Garant für eine gesicherte Zukunft in der Forschung. Wer sechs Jahre nach der Promotion den Sprung zur Professur nicht geschafft hat, geht einer ungewissen Zukunft als Privatdozent entgegen. Seit einigen Jahren gibt es neben der Habilitation noch einen zweiten Weg zur Professur- die Juniorprofessur. Auch an der Universität Potsdam gibt es seit 2002 Juniorprofessoren, von denen die ersten jetzt evaluiert wurden. Näheres dazu finden Sie ebenfalls in der Rubrik "wissenstransfer". Wer noch nach einer Finanzierungsmöglichkeit für seine Promotion sucht, findet Tipps in der Rubrik "wegweiser". Die Redaktion wünscht Ihnen viel Vergnügen beim Lesen von Portal alumni und freut sich auf zahlreiche Leserbriefe.
N2 - Dear readers, many students dream of researching the world's inner and outermost secrets. Still, what sacrifice must one bring in order to achieve this goa/, and what are the professional perspectives being offered to researchers today? Many University of Potsdom alumni have to find answers to these questions as weil. in the section "forscher/eben", a number of alumni discuss their answers, the problems that they have encountered along the way, the enJoyment that they have received through their research and their worries for the future. In Germany, the funding of research on part ofboth the state and the corporate world is sparsein comparison to other leading industrial countries, and the current opportunities for researchers are clearly not the best. in the section ,.wissenstransfer", the president of the Frauenhofer-Gesellschaft, Prof Dr. Hans-jörg Bullinger, discusses how Germany is losing its future potential in the process. Indeed, the university is no guarantee for a secure profossianal future in the research field. A few years ago, the Junior professorship was created as a second path to a Juli professorship, next to the traditional postdoctoral qualification (Habilitation). in 2002, the University of Potsdom began to establish Junior professorships. The first of these are currently being evaluated. More information on this process can be found in the section "wissenstransfer". In addition, suggestions and tips can be found in the section "wegweiser" for those who are seekingfunding opportunities for their dissertation work.
T3 - Portal alumni : das Ehemaligen-Magazin der Universität Potsdam - 3/2005
Y1 - 2005
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-481608
VL - 2005
IS - 3
EP - 58
ER -
TY - CHAP
A1 - Lück, Erika
A1 - Balderjahn, Ingo
A1 - Kamm, Birgit
A1 - Greil, Holle
A1 - Wallschläger, Hans-Dieter
A1 - Jessel, Beate
A1 - Böckmann, Christine
A1 - Oberhänsli, Roland
A1 - Soyez, Konrad
A1 - Schmeer, Ernst
A1 - Blumenstein, Oswald
A1 - Berndt, Klaus-Peter
A1 - Edeling, Thomas
A1 - Friedrich, Sabine
A1 - Kaden, Klaus
A1 - Scheller, Frieder W.
A1 - Petersen, Hans-Georg
A1 - Asche, Hartmut
A1 - Bronstert, Axel
A1 - Giest, Hartmut
A1 - Gaedke, Ursula
A1 - Löhmannsröben, Hans-Gerd
A1 - Jeltsch, Florian
A1 - Jänkel, Ralph
A1 - Gzik, Axel
A1 - Bork, Hans-Rudolf
A1 - Bork, Hans-Rudolf
T1 - Umweltforschung für das Land Brandenburg : Arbeitsgruppen und Professuren
Y1 - 2000
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-3797
ER -
TY - BOOK
A1 - Rana, Kaushik
A1 - Mohapatra, Durga Prasad
A1 - Sidorova, Julia
A1 - Lundberg, Lars
A1 - Sköld, Lars
A1 - Lopes Grim, Luís Fernando
A1 - Sampaio Gradvohl, André Leon
A1 - Cremerius, Jonas
A1 - Siegert, Simon
A1 - Weltzien, Anton von
A1 - Baldi, Annika
A1 - Klessascheck, Finn
A1 - Kalancha, Svitlana
A1 - Lichtenstein, Tom
A1 - Shaabani, Nuhad
A1 - Meinel, Christoph
A1 - Friedrich, Tobias
A1 - Lenzner, Pascal
A1 - Schumann, David
A1 - Wiese, Ingmar
A1 - Sarna, Nicole
A1 - Wiese, Lena
A1 - Tashkandi, Araek Sami
A1 - van der Walt, Estée
A1 - Eloff, Jan H. P.
A1 - Schmidt, Christopher
A1 - Hügle, Johannes
A1 - Horschig, Siegfried
A1 - Uflacker, Matthias
A1 - Najafi, Pejman
A1 - Sapegin, Andrey
A1 - Cheng, Feng
A1 - Stojanovic, Dragan
A1 - Stojnev Ilić, Aleksandra
A1 - Djordjevic, Igor
A1 - Stojanovic, Natalija
A1 - Predic, Bratislav
A1 - González-Jiménez, Mario
A1 - de Lara, Juan
A1 - Mischkewitz, Sven
A1 - Kainz, Bernhard
A1 - van Hoorn, André
A1 - Ferme, Vincenzo
A1 - Schulz, Henning
A1 - Knigge, Marlene
A1 - Hecht, Sonja
A1 - Prifti, Loina
A1 - Krcmar, Helmut
A1 - Fabian, Benjamin
A1 - Ermakova, Tatiana
A1 - Kelkel, Stefan
A1 - Baumann, Annika
A1 - Morgenstern, Laura
A1 - Plauth, Max
A1 - Eberhard, Felix
A1 - Wolff, Felix
A1 - Polze, Andreas
A1 - Cech, Tim
A1 - Danz, Noel
A1 - Noack, Nele Sina
A1 - Pirl, Lukas
A1 - Beilharz, Jossekin Jakob
A1 - De Oliveira, Roberto C. L.
A1 - Soares, Fábio Mendes
A1 - Juiz, Carlos
A1 - Bermejo, Belen
A1 - Mühle, Alexander
A1 - Grüner, Andreas
A1 - Saxena, Vageesh
A1 - Gayvoronskaya, Tatiana
A1 - Weyand, Christopher
A1 - Krause, Mirko
A1 - Frank, Markus
A1 - Bischoff, Sebastian
A1 - Behrens, Freya
A1 - Rückin, Julius
A1 - Ziegler, Adrian
A1 - Vogel, Thomas
A1 - Tran, Chinh
A1 - Moser, Irene
A1 - Grunske, Lars
A1 - Szárnyas, Gábor
A1 - Marton, József
A1 - Maginecz, János
A1 - Varró, Dániel
A1 - Antal, János Benjamin
ED - Meinel, Christoph
ED - Polze, Andreas
ED - Beins, Karsten
ED - Strotmann, Rolf
ED - Seibold, Ulrich
ED - Rödszus, Kurt
ED - Müller, Jürgen
T1 - HPI Future SOC Lab – Proceedings 2018
N2 - The “HPI Future SOC Lab” is a cooperation of the Hasso Plattner Institute (HPI) and industry partners. Its mission is to enable and promote exchange and interaction between the research community and the industry partners.
The HPI Future SOC Lab provides researchers with free of charge access to a complete infrastructure of state of the art hard and software. This infrastructure includes components, which might be too expensive for an ordinary research environment, such as servers with up to 64 cores and 2 TB main memory. The offerings address researchers particularly from but not limited to the areas of computer science and business information systems. Main areas of research include cloud computing, parallelization, and In-Memory technologies.
This technical report presents results of research projects executed in 2018. Selected projects have presented their results on April 17th and November 14th 2017 at the Future SOC Lab Day events.
N2 - Das Future SOC Lab am HPI ist eine Kooperation des Hasso-Plattner-Instituts mit verschiedenen Industriepartnern. Seine Aufgabe ist die Ermöglichung und Förderung des Austausches zwischen Forschungsgemeinschaft und Industrie.
Am Lab wird interessierten Wissenschaftler:innen eine Infrastruktur von neuester Hard- und Software kostenfrei für Forschungszwecke zur Verfügung gestellt. Dazu zählen Systeme, die im normalen Hochschulbereich in der Regel nicht zu finanzieren wären, bspw. Server mit bis zu 64 Cores und 2 TB Hauptspeicher. Diese Angebote richten sich insbesondere an Wissenschaftler:innen in den Gebieten Informatik und Wirtschaftsinformatik. Einige der Schwerpunkte sind Cloud Computing, Parallelisierung und In-Memory Technologien.
In diesem Technischen Bericht werden die Ergebnisse der Forschungsprojekte des Jahres 2018 vorgestellt. Ausgewählte Projekte stellten ihre Ergebnisse am 17. April und 14. November 2018 im Rahmen des Future SOC Lab Tags vor.
T3 - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 151
KW - Future SOC Lab
KW - research projects
KW - multicore architectures
KW - in-memory technology
KW - cloud computing
KW - machine learning
KW - artifical intelligence
KW - Future SOC Lab
KW - Forschungsprojekte
KW - Multicore Architekturen
KW - In-Memory Technologie
KW - Cloud Computing
KW - maschinelles Lernen
KW - künstliche Intelligenz
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-563712
SN - 978-3-86956-547-7
SN - 1613-5652
SN - 2191-1665
IS - 151
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - JOUR
A1 - Kappel, Christian
A1 - Friedrich, Thomas
A1 - Oberkofler, Vicky
A1 - Jiang, Li
A1 - Crawford, Tim
A1 - Lenhard, Michael
A1 - Bäurle, Isabel
T1 - Genomic and epigenomic determinants of heat stress-induced transcriptional memory in Arabidopsis
JF - Genome biology : biology for the post-genomic era
N2 - Background
Transcriptional regulation is a key aspect of environmental stress responses. Heat stress induces transcriptional memory, i.e., sustained induction or enhanced re-induction of transcription, that allows plants to respond more efficiently to a recurrent HS. In light of more frequent temperature extremes due to climate change, improving heat tolerance in crop plants is an important breeding goal. However, not all heat stress-inducible genes show transcriptional memory, and it is unclear what distinguishes memory from non-memory genes. To address this issue and understand the genome and epigenome architecture of transcriptional memory after heat stress, we identify the global target genes of two key memory heat shock transcription factors, HSFA2 and HSFA3, using time course ChIP-seq.
Results
HSFA2 and HSFA3 show near identical binding patterns. In vitro and in vivo binding strength is highly correlated, indicating the importance of DNA sequence elements. In particular, genes with transcriptional memory are strongly enriched for a tripartite heat shock element, and are hallmarked by several features: low expression levels in the absence of heat stress, accessible chromatin environment, and heat stress-induced enrichment of H3K4 trimethylation. These results are confirmed by an orthogonal transcriptomic data set using both de novo clustering and an established definition of memory genes.
Conclusions
Our findings provide an integrated view of HSF-dependent transcriptional memory and shed light on its sequence and chromatin determinants, enabling the prediction and engineering of genes with transcriptional memory behavior.
KW - Transcriptional memory
KW - Priming
KW - Heat stress
KW - HSFA2
KW - HSFA3
KW - Arabidopsis thaliana
KW - Histone H3K4 trimethylation
KW - ChIP-seq
Y1 - 2023
U6 - https://doi.org/10.1186/s13059-023-02970-5
SN - 1474-760X
VL - 24
IS - 1
PB - BioMed Central
CY - London
ER -
TY - BOOK
A1 - Kuban, Robert
A1 - Rotta, Randolf
A1 - Nolte, Jörg
A1 - Chromik, Jonas
A1 - Beilharz, Jossekin Jakob
A1 - Pirl, Lukas
A1 - Friedrich, Tobias
A1 - Lenzner, Pascal
A1 - Weyand, Christopher
A1 - Juiz, Carlos
A1 - Bermejo, Belen
A1 - Sauer, Joao
A1 - Coelh, Leandro dos Santos
A1 - Najafi, Pejman
A1 - Pünter, Wenzel
A1 - Cheng, Feng
A1 - Meinel, Christoph
A1 - Sidorova, Julia
A1 - Lundberg, Lars
A1 - Vogel, Thomas
A1 - Tran, Chinh
A1 - Moser, Irene
A1 - Grunske, Lars
A1 - Elsaid, Mohamed Esameldin Mohamed
A1 - Abbas, Hazem M.
A1 - Rula, Anisa
A1 - Sejdiu, Gezim
A1 - Maurino, Andrea
A1 - Schmidt, Christopher
A1 - Hügle, Johannes
A1 - Uflacker, Matthias
A1 - Nozza, Debora
A1 - Messina, Enza
A1 - Hoorn, André van
A1 - Frank, Markus
A1 - Schulz, Henning
A1 - Alhosseini Almodarresi Yasin, Seyed Ali
A1 - Nowicki, Marek
A1 - Muite, Benson K.
A1 - Boysan, Mehmet Can
A1 - Bianchi, Federico
A1 - Cremaschi, Marco
A1 - Moussa, Rim
A1 - Abdel-Karim, Benjamin M.
A1 - Pfeuffer, Nicolas
A1 - Hinz, Oliver
A1 - Plauth, Max
A1 - Polze, Andreas
A1 - Huo, Da
A1 - Melo, Gerard de
A1 - Mendes Soares, Fábio
A1 - Oliveira, Roberto Célio Limão de
A1 - Benson, Lawrence
A1 - Paul, Fabian
A1 - Werling, Christian
A1 - Windheuser, Fabian
A1 - Stojanovic, Dragan
A1 - Djordjevic, Igor
A1 - Stojanovic, Natalija
A1 - Stojnev Ilic, Aleksandra
A1 - Weidmann, Vera
A1 - Lowitzki, Leon
A1 - Wagner, Markus
A1 - Ifa, Abdessatar Ben
A1 - Arlos, Patrik
A1 - Megia, Ana
A1 - Vendrell, Joan
A1 - Pfitzner, Bjarne
A1 - Redondo, Alberto
A1 - Ríos Insua, David
A1 - Albert, Justin Amadeus
A1 - Zhou, Lin
A1 - Arnrich, Bert
A1 - Szabó, Ildikó
A1 - Fodor, Szabina
A1 - Ternai, Katalin
A1 - Bhowmik, Rajarshi
A1 - Campero Durand, Gabriel
A1 - Shevchenko, Pavlo
A1 - Malysheva, Milena
A1 - Prymak, Ivan
A1 - Saake, Gunter
ED - Meinel, Christoph
ED - Polze, Andreas
ED - Beins, Karsten
ED - Strotmann, Rolf
ED - Seibold, Ulrich
ED - Rödszus, Kurt
ED - Müller, Jürgen
T1 - HPI Future SOC Lab – Proceedings 2019
N2 - The “HPI Future SOC Lab” is a cooperation of the Hasso Plattner Institute (HPI) and industry partners. Its mission is to enable and promote exchange and interaction between the research community and the industry partners.
The HPI Future SOC Lab provides researchers with free of charge access to a complete infrastructure of state of the art hard and software. This infrastructure includes components, which might be too expensive for an ordinary research environment, such as servers with up to 64 cores and 2 TB main memory. The offerings address researchers particularly from but not limited to the areas of computer science and business information systems. Main areas of research include cloud computing, parallelization, and In-Memory technologies.
This technical report presents results of research projects executed in 2019. Selected projects have presented their results on April 9th and November 12th 2019 at the Future SOC Lab Day events.
N2 - Das Future SOC Lab am HPI ist eine Kooperation des Hasso-Plattner-Instituts mit verschiedenen Industriepartnern. Seine Aufgabe ist die Ermöglichung und Förderung des Austausches zwischen Forschungsgemeinschaft und Industrie.
Am Lab wird interessierten Wissenschaftlern eine Infrastruktur von neuester Hard- und Software kostenfrei für Forschungszwecke zur Verfügung gestellt. Dazu zählen teilweise noch nicht am Markt verfügbare Technologien, die im normalen Hochschulbereich in der Regel nicht zu finanzieren wären, bspw. Server mit bis zu 64 Cores und 2 TB Hauptspeicher. Diese Angebote richten sich insbesondere an Wissenschaftler in den Gebieten Informatik und Wirtschaftsinformatik. Einige der Schwerpunkte sind Cloud Computing, Parallelisierung und In-Memory Technologien.
In diesem Technischen Bericht werden die Ergebnisse der Forschungsprojekte des Jahres 2019 vorgestellt. Ausgewählte Projekte stellten ihre Ergebnisse am 09. April und 12. November 2019 im Rahmen des Future SOC Lab Tags vor.
T3 - Technische Berichte des Hasso-Plattner-Instituts für Digital Engineering an der Universität Potsdam - 158
KW - Future SOC Lab
KW - research projects
KW - multicore architectures
KW - in-memory technology
KW - cloud computing
KW - machine learning
KW - artifical intelligence
KW - Future SOC Lab
KW - Forschungsprojekte
KW - Multicore Architekturen
KW - In-Memory Technologie
KW - Cloud Computing
KW - maschinelles Lernen
KW - künstliche Intelligenz
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-597915
SN - 978-3-86956-564-4
SN - 1613-5652
SN - 2191-1665
IS - 158
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - JOUR
A1 - Hempel, Hannes
A1 - Savenjie, Tom J.
A1 - Stolterfoht, Martin
A1 - Neu, Jens
A1 - Failla, Michele
A1 - Paingad, Vaisakh C.
A1 - Kužel, Petr
A1 - Heilweil, Edwin J.
A1 - Spies, Jacob A.
A1 - Schleuning, Markus
A1 - Zhao, Jiashang
A1 - Friedrich, Dennis
A1 - Schwarzburg, Klaus
A1 - Siebbeles, Laurens D. A.
A1 - Dörflinger, Patrick
A1 - Dyakonov, Vladimir
A1 - Katoh, Ryuzi
A1 - Hong, Min Ji
A1 - Labram, John G.
A1 - Monti, Maurizio
A1 - Butler-Caddle, Edward
A1 - Lloyd-Hughes, James
A1 - Taheri, Mohammad M.
A1 - Baxter, Jason B.
A1 - Magnanelli, Timothy J.
A1 - Luo, Simon
A1 - Cardon, Joseph M.
A1 - Ardo, Shane
A1 - Unold, Thomas
T1 - Predicting solar cell performance from terahertz and microwave spectroscopy
JF - Advanced energy materials
N2 - Mobilities and lifetimes of photogenerated charge carriers are core properties of photovoltaic materials and can both be characterized by contactless terahertz or microwave measurements. Here, the expertise from fifteen laboratories is combined to quantitatively model the current-voltage characteristics of a solar cell from such measurements. To this end, the impact of measurement conditions, alternate interpretations, and experimental inter-laboratory variations are discussed using a (Cs,FA,MA)Pb(I,Br)(3) halide perovskite thin-film as a case study. At 1 sun equivalent excitation, neither transport nor recombination is significantly affected by exciton formation or trapping. Terahertz, microwave, and photoluminescence transients for the neat material yield consistent effective lifetimes implying a resistance-free JV-curve with a potential power conversion efficiency of 24.6 %. For grainsizes above approximate to 20 nm, intra-grain charge transport is characterized by terahertz sum mobilities of approximate to 32 cm(2) V-1 s(-1). Drift-diffusion simulations indicate that these intra-grain mobilities can slightly reduce the fill factor of perovskite solar cells to 0.82, in accordance with the best-realized devices in the literature. Beyond perovskites, this work can guide a highly predictive characterization of any emerging semiconductor for photovoltaic or photoelectrochemical energy conversion. A best practice for the interpretation of terahertz and microwave measurements on photovoltaic materials is presented.
KW - lifetime
KW - microwaves
KW - mobility
KW - solar cells
KW - terahertz
Y1 - 2022
U6 - https://doi.org/10.1002/aenm.202102776
SN - 1614-6832
SN - 1614-6840
VL - 12
IS - 13
PB - Wiley
CY - Weinheim
ER -
TY - JOUR
A1 - Friedrich, Thomas
A1 - Faivre, Lea
A1 - Bäurle, Isabel
A1 - Schubert, Daniel
T1 - Chromatin-based mechanisms of temperature memory in plants
JF - Plant, cell & environment : cell physiology, whole-plant physiology, community physiology
N2 - For successful growth and development, plants constantly have to gauge their environment. Plants are capable to monitor their current environmental conditions, and they are also able to integrate environmental conditions over time and store the information induced by the cues. In a developmental context, such an environmental memory is used to align developmental transitions with favourable environmental conditions. One temperature-related example of this is the transition to flowering after experiencing winter conditions, that is, vernalization. In the context of adaptation to stress, such an environmental memory is used to improve stress adaptation even when the stress cues are intermittent. A somatic stress memory has now been described for various stresses, including extreme temperatures, drought, and pathogen infection. At the molecular level, such a memory of the environment is often mediated by epigenetic and chromatin modifications. Histone modifications in particular play an important role. In this review, we will discuss and compare different types of temperature memory and the histone modifications, as well as the reader, writer, and eraser proteins involved.
KW - chromatin
KW - cold
KW - epigenetics
KW - heat
KW - memory
KW - nucleosome remodelling
KW - polycomb
KW - priming
KW - trithorax
Y1 - 2018
U6 - https://doi.org/10.1111/pce.13373
SN - 0140-7791
SN - 1365-3040
VL - 42
IS - 3
SP - 762
EP - 770
PB - Wiley
CY - Hoboken
ER -